层间电荷转移铁电波动作为范德瓦耳斯超导体中配对机制
Interlayer Charge-Transfer Ferroelectric Fluctuations as a Pairing Mechanism in van der Waals Superconductors
AI总结：
研究发现层间铁电波动可通过产生强耦合配对相互作用，为范德瓦耳斯超导体中的非常规配对机制提供新途径。
摘要：
在广泛的范德瓦耳斯（vdW）材料中已报告了非常规超导性的迹象。然而，由于正常态中竞争的电子有序、强自旋-轨道耦合和结构不稳定性，其微观起源仍然不清楚。本文研究了层间呼吸和剪切模式在超导vdW异质结构中的作用。与传统观点相反——即弱层间键合和大层间距离会抑制电子耦合到这些模式——我们证明相关的电荷转移可以产生显著的配对相互作用。我们发展了由这些层间模式介导的超导理论，并证明接近铁电或反铁电量子临界点会提供强耦合配对通道。在具有SU(2)对称性和平面各向同性的二维模型中，我们发现层间三重态之间存在意外简并，即使对于s波平面间隙也是如此。我们进一步表明，层间约瑟夫森耦合，无论是由于静态磁性还是由顺磁相关性诱导，都能稳定一种打破时间反演对称性的s+i s型超导态，该态在至少两个镜像对称性缺失时与磁化耦合。我们的结果直接适用于候选的左手vdW超导体，如4Hb-TaS₂，以及滑动铁电金属，如双层MoTe₂。更广泛地说，我们的工作将铁电波动识别为在vdW系统中实现非常规配对的有希望的途径，并激发了对左手多组分超导性的实验搜索。
英文摘要：
Signatures of unconventional superconductivity have been reported in a wide range of van der Waals (vdW) materials. However, their microscopic origin remains unclear due to competing electronic orders, strong spin-orbit coupling, and structural instabilities in the normal state. Here we investigate the role of interlayer breathing and shear modes in superconducting vdW heterostructures. Contrary to conventional wisdom -- which assumes that weak interlayer bonding and large layer separation suppress electronic coupling to these modes -- we show that the associated charge transfer can generate a substantial pairing interaction. We develop a theory of superconductivity mediated by such interlayer modes and demonstrate that proximity to a ferroelectric or antiferroelectric quantum critical point provides a strong-coupling pairing channel. Within a two-dimensional model with SU(2) symmetry and in-plane isotropy, we find an accidental degeneracy between interlayer triplet states, which can occur even for an $s$-wave in-plane gap. We further show that Josephson coupling between layers, arising from either static magnetism or induced by paramagnetic correlations, can stabilize a time-reversal-symmetry-breaking superconducting state of the $s+i\,s$ type, which couples to magnetization when at least two mirror symmetries are absent. Our results are directly applicable to candidate chiral vdW superconductors such as 4Hb-TaS$_2$ and to sliding ferroelectric metals, exemplified by bilayer MoTe$_2$. More broadly, our work identifies ferroelectric fluctuations as a promising route to unconventional pairing in vdW systems and motivates experimental searches for chiral multicomponent superconductivity.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
